The present invention relates to an injection syringe including a device for preparation of an injection (plural: injections). More particularly, the present invention relates to an injection syringe provided with a structure in which an unstable freeze dried medicine and a medicinal solvent are stored in separate spaces and an injection is readily prepared by dissolution of the unstable freeze dried medicine into the medicinal solvent as necessary in situ, in place of the conventional preparation that the unstable freeze dried medicine and the medicinal solvent have been stored in traditional vials.
The present invention is applicable to a wide range of chemicals traditionally stored in vials, and is also applicable to such unstable chemicals as will suffer chemical changes if stored in the status of solution or dispersion for a long period. Thereby, a patient who is required to carry the injection kit with him and perform the injection for himself is conveniently enabled to do so, wherein the control of a dosage is also enabled.
Conventionally, chemicals for injection use have been stored in the sterile environment or sealed in vials. In preparing the injection, the solvent is taken up from the solvent vial and charged into the solid medicine vial for dissolution. However, such operation possibly includes chances to attract microorganisms, fine foreign matters such as fine glass or rubber fragments. Further, the transfer act of the dissolution stored in the vial to the injection syringe has sometimes suffered from misoperations. In addition, it has taken a considerable time to finish the preparation for the injection, difficult to comply with an urgent case, and a wide space is required to support such operations because a number of vessels or tools are involved.
Traditionally, where a patient has to sit for injections regularly for a long period, for instance, injections of human growth hormones or insulin, such system has been employed as the patient always carries the kit of injection syringe and performs injections for himself. In this application, an injection syringe should be ready to be assembled by himself and there has been known the injection syringe for multiple usage by exchange of the ampule and the needle.
Heretofore, when a unstable freeze dried medicine after dissolution is difficult to store for long time, the medicine and the solvent therefor have been stored in vials separately. The injection is prepared with use of the vials and thereafter transferred to the injection syringe to perform the injection. The task has remained in the point of facilitating traditional operations and avoiding possible inclusion of foreign matters or microorganisms, and overcoming misoperations possible during complex procedure, inability to comply with an urgent case, the present invention is intended to develop the apparatus and process for storing the medicine and the solvent separately inside the injection syringe to prepare for the injection also inside the same injection syringe. The consequent injection should be applicable in situ as necessary.
In view of such task as noted above, the present invention is accomplished with start from the multichambered injection syringe used to unstable substances, such as human growth hormones, interferon, other polypeptides and by adding some simple structures to such injection syringe, including a device for accommodating the cylindrical ampule inside the injection apparatus, and a device for storing the injection without a reverse flow occurring in the ampule interior during the time from the preparation of the injection to the performance of the injection, and a device for ready performance in situ as necessary, further devices such as for adjusting a dosage amount as well as for connecting the injection syringe with the tridirectional valve.